This invention relates to an air flow control mechanism, and more particularly, to an air flow control mechanism for radiators.
It has long been known that the heat transfer of cooling air through a radiator core can be controlled by using a plurality of adjustable shutters, such as shown in U.S. Pat. No. 1,329,589 to Fedders. Some of the prior art radiator systems incorporate the adjustable shutters within the radiator core structure, as shown by U.S. Pat. No. 1,352,190 to Hamilton.
The effectiveness of a heat transfer device, such as a radiator, depends on close contact of the flowing fluid with the heat transfer surface. This effectiveness is frequently diminished by the formation of a boundary layer of stagnant air. All of the above mentioned prior art radiator systems have this disadvantage because they have no means to eliminate or diminish the boundary layer by creating turbulence in the air stream passing through the radiator core.
It has been recognized by some sources that reversing the direction of air flow over the cooling surfaces will prevent the formation of a boundary layer to thereby improve their heat transfer effectiveness. One prior art means of accomplishing this was to construct the surface in the form of a cylinder which is rotated so that the air flows radially inward across the surface than radially outward as a second pass. The disadvantage of this system is that is requires extensive changes to the engine compartment, accessories, drives and the like to accommodate the drum and ducting required.
This invention uses the reverse cycling technique for eliminating the boundary layer by a simple modification to existing current cooling systems.